Veto Pro Pac SP-MC cup holder

I used 3x M4x12 countersunk screws for my prototype. For your final print, you could definitely use longer screws and/or threaded inserts. I would recommend still using countersunk screws, though, as the screw heads might interfere with your bottle if you don't. I tried to implement a countersink in the model for non-countersunk screws, but it didn't work. Feel free to remix if you want to improve the design or think of other attachments for the outside.

This model fits the 28oz Blender Bottle (V1 and V2), It should fit most, if not all, 20oz water/soda bottles.